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Zheng et al. Soft Sci. 2026, 6, 32 Page 17 of 57

method’s success. Dispersions that are too diluted (less than 1 mg·mL ) do not create continuous hydrogel
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networks; instead, they produce fragmented microgels instead of whole fibers. On the other hand, excessively
high viscosity in highly concentrated dispersions (> 15 mg·mL ) makes capillary injection more difficult and
-1
increases blockage susceptibility. Strongly alkaline circumstances encourage excessive reduction and
aggregation of GO before orderly assembly, therefore a pH that is slightly acidic or almost neutral is ideal.

Restricted hydrothermal assembly’s main selling points are its ease of use and capacity to create unusual
microstructured fibers that are challenging to do using wet spinning. Extended reaction durations (usually
ranging from several hours to days), batch-operated methods limited by capillary length, and a high
sensitivity of the final fiber quality to the drying process are some of the technique’s inherent drawbacks. The
difficulty of attaining repeatable process control was highlighted by a systematic study by Wang et al. that
showed how various drying protocols (such as ambient-temperature drying and supercritical CO drying)
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drastically change the pore structure and volumetric properties of the fibers [Figure 6K and L] . In order to
[86]
get over the limits of batch production, Ding et al. suggested a hybrid approach that involves hydrothermally
treating porous graphene microgels first, then combining them with GO spinning slurry for continuous wet
spinning . As shown in Figure 6M, this method effectively combined the scalability of wet spinning with
[87]
the structural benefits of hydrothermal assembly (high specific surface area, porous architecture).

Film twisting and template-assisted CVD
Although the goal of both of these essentially different processes is to create GFs from premium graphene
sheets, their working principles are completely different and they function separately.

Twisting technique for films. This method uses mechanical twisting and winding to convert existing
two-dimensional graphene assemblies into one-dimensional fibers. There are several ways to manufacture
the first film, including growing it directly by chemical vapour deposition on a metal substrate and then
transferring it, or chemically rGO after vacuum filtration. In order to create hybrid fibers, Zhang’s group [89]
used a two-step process, first depositing GO onto CNT fiber scaffolds and then decreasing it. Low interlayer
bonding strength frequently leads to low tensile strength and restricted preparation efficiency, even when
highly extensible fibers can be produced. The scalability and mechanical qualities of film twisting technology
continue to be major obstacles, despite the fact that it provides flexibility in film sourcing.

Chemical vapour deposition with the use of a template. Graphene is grown directly on one-dimensional
templates (such as copper wires or quartz optical fibers) using CVD. After growth, the template can either be
kept to create composite fibers or removed to produce hollow GFs [Figure 7A]. Recent developments have
greatly improved mechanistic knowledge and process scalability. Li et al. demonstrated the feasibility of
roll-to-roll manufacturing and proposed a novel “gas-surface-solid”growth mechanism by achieving
low-temperature, high-speed graphene synthesis on alumina fiber fabrics [Figure 7B] . Chen and Dai
[90]
created porous GFs for fiber-based solar cells using copper wires as templates . Graphene was grown on
[96]
glass fibers by Yuan et al. to create high-performance infrared electrothermal textiles [Figure 7C] .
[57]
Although the procedure usually entails template removal steps and lacks the continuity of wet spinning
methods, these examples demonstrate the potential of template-assisted CVD approaches for the synthesis of
structurally controlled, high-quality GFs.

These works show great potential for high-end applications and expand the selection of templates. In
conclusion, the aforementioned techniques offer a variety of technological approaches for the fabrication of
GFs, each with unique benefits in the areas of orientation control, porosity design, nanostructure
construction, and high-efficiency graphene production. Continuous production, cost management, process
stability, and attaining balanced comprehensive performance are still difficult tasks, nevertheless. In order to